Destructive insects known for killing ash trees have been found in new locations in northeast Iowa.
The state Department of Natural Resources says insect larvae consistent with the emerald ash borer have been found in two trees in Allamakee County.
The county has been under quarantine since 2010 when the insect was discovered along the Mississippi River.
Officials say the discoveries are the furthest west the invasive pests have been spotted. It also is the first time emerald ash borer has been found in sentinel trees in the state. Those are trees purposely girdled to attract the beetles. More than 400 of those trees are being checked as part of a surveillance effort.
Nearly 1,200 insect traps were placed this summer, mostly in eastern Iowa.